Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

935
FXUS63 KLOT 022326
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
526 PM CST Sun Nov 2 2025

.KEY MESSAGES...

- Seasonably mild, frequently breezy, and dry through midweek.

- Best chance for measurable rain this workweek will be late
  Thursday night into Friday morning.

- Turning sharply cooler next weekend.

&&

.DISCUSSION...
Issued at 206 PM CST Sun Nov 2 2025

A cold front trailing from deep surface low pressure over Hudson
Bay will approach tonight and sweep across the area by early to
mid Monday morning. A stout southwesterly low-level jet will
develop in the frontal trough and should enable occasional gusts
to 20-30 mph near/north of I-80 in the late evening and overnight.
The strongest and most frequent gusts will likely be from
Chicago and points north where temperatures won`t drop off as
much this evening and support a bit better mixing. There may be
spotty sprinkles and perhaps a few bonafide showers as a plume
of mid-level moisture traverses southeast in concert with good
large scale forcing. The best chance (about 20%) for measurable
rain in any showers is across far northeast Illinois.

Only modest cold air advection in the wake of the cold front,
full sunshine during our brief window of peak heating, and deep
mixing forcing dew points down into the 20s will yield highs in
the upper 50s to lower 60s. Breezy west-northwest winds gusting
to 25-30 mph, will make it feel a bit cooler, however. Surface
high pressure will center south of the Ohio Valley Monday night,
though its ridge axis will extend to the upper MS Valley,
resulting in a calm and seasonably chilly night, though
increasing clouds overnight will limit how cold it will get.

The northern branch of the jet stream will remain fairly active
through the week, resulting in a continued parade of cold
frontal passages. Out ahead of each front, expect breezy and
mild conditions (low-mid 60s area-wide Tuesday and mid to even
upper 60s Wednesday south of I-80). Thursday will start chilly
but then recover into the 50s to around 60F during the
afternoon. The Thursday night into Friday morning cold frontal
approach and passage will likely finally have enough moisture
for showers (possibly even a few embedded t-storms prior to
daybreak Friday). PoPs peaking in the 50-60% range appear
reasonable at this juncture. Friday afternoon should dry out in
breezy westerly flow behind the front.

Forecast confidence drops off into next weekend regarding the
timing of a secondary reinforcing shot of much cooler air. If
another clipper-like system affects the region on Saturday, we
may squeeze out one more mild day, albeit with a chance of light
rain into the evening. Next Sunday will probably be the coolest
day of our pleasant autumn thus far, with highs only in the
40s, followed by a hard freeze for many locations Sunday night.

Castro

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 526 PM CST Sun Nov 2 2025

Key Aviation Messages for the current TAF period:

- LLWS overnight into early Monday morning

- Westerly wind gusts potentially as high as 30 kt on Monday

Southwest winds may occasionally gust to around 20 knots in the
short term, but winds are slowly diminishing now that the sun
has set.

A weak cold front will pass over the area overnight. Most areas
should remain dry, but cannot rule out a sprinkle occurring.
The bigger impact with the front is a strengthening low level
jet after 03Z, where winds 2000 ft AGL could be 40-45+ kt.
Surface gusts over 20 knots was kept in the TAF, but models are
trending with better decoupling which would allow gusts to cut
off. Therefore low level wind shear was kept in the TAF
overnight with improving conditions after daybreak.

Winds will slowly become westerly, if not just north of true
west, after daybreak tomorrow. Deeper mixing will allow for
gusts 20 to 25 knots to prevail for much of the daytime hours,
with strongest gusts expected in the afternoon with peak gusts
up to 30 knots. Winds should decouple fairly quickly after
sunset tomorrow night.

DK

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 5 PM CST Monday for the IL
     nearshore waters.

     Small Craft Advisory from 9 PM this evening to 5 PM CST Monday
     for the IN nearshore waters.

&&

$$

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